OpenGL（三）MFC中应用OpenGL的两个类

• 网上找了下MFC中应用OpenGL的方法，总觉得不太方便，到处复制一堆堆函数，于是封装了两个类（CmyOpenGL和CRenderContex）。方便应用。
• 以MFC Dialog为例添加步骤：
  • CXXXDlg中添加一CmyOpenGL成员（或指针，别忘记释放就行）
  • 将三个成员函数对应加入（OnCreate、OnPaint、OnSize）MFC的消息映射函数中，传递相应参数（CmyOpenGL要利用CDC*所指对象，因此CDC*要在CmyOpenGL对象之后释放！）
• 代码：
  • CmyOpenGL.h

    #pragma once
    #include "RenderContex.h"
    
    class CmyOpenGL
    {
    public:
        CmyOpenGL(void);
        virtual ~CmyOpenGL(void);
    public:
        virtual void OnCreate(CDC* pDC);
        virtual void OnPaint(void);
        virtual void OnSize(int cx, int cy);
    private:
        virtual void RenderScene (void);
    private:
        CDC* m_pDC;
        CRenderContex* m_pRC;
    };

  • CmyOpenGL.cpp

    #include "StdAfx.h"
    #include "myOpenGL.h"
    
    CmyOpenGL::CmyOpenGL(void)
    {
        m_pDC = NULL;
        m_pRC = NULL;
    }
    
    CmyOpenGL::~CmyOpenGL(void)
    {
        if (m_pRC)
        {
            delete m_pRC;
        }
        m_pRC = NULL;
    }
    
    void CmyOpenGL::OnCreate(CDC* pDC)
    {
        ASSERT(pDC);
        m_pRC = new CRenderContex(pDC);
        ASSERT(m_pRC);
    
        m_pDC = pDC;
    
        //Specify Black as the clear color
        ::glClearColor(0.0f,0.0f,0.0f,0.0f);
    }
    
    void CmyOpenGL::OnPaint()
    {
        // Clear out the color & depth buffers
        ::glClear( GL_COLOR_BUFFER_BIT);
        RenderScene();
        // Tell OpenGL to flush its pipeline
        ::glFinish();
        // Now Swap the buffers
        ::SwapBuffers( m_pDC->GetSafeHdc() );
    }
    
    void CmyOpenGL::OnSize(int cx, int cy)
    {
        if ( 0 >= cx || 0 >= cy )
        {
            return;
        }
        // select the full client area
        ::glViewport(0, 0, cx, cy);
        // select the projection matrix and clear it
        ::glMatrixMode(GL_PROJECTION);
        ::glLoadIdentity();
        // select the viewing volume
        ::gluPerspective(45.0f, (GLdouble)cx/(GLdouble)cy, 1.0f, 100.0f);
        // switch back to the modelview matrix and clear it
        ::glMatrixMode(GL_MODELVIEW);
        ::glLoadIdentity();
    }
    
    void CmyOpenGL::RenderScene (void)
    {
        glTranslatef(0.0f, 0.0f, -5.0f);
        glRotatef(45.0,0.0,1.0,0.0);
        glutWireCube(1.0);
    }

  • CRenderContex.h

    #pragma once
    
    class CRenderContex
    {
    public:
        CRenderContex(CDC *pDC);
        ~CRenderContex(void);
    private:
        BOOL SetupPixelFormat(CDC *pDC);    //Set up the Pixel Format
    private:
        HGLRC m_hRC;
    };

  • CRenderContex.cpp

    #include "StdAfx.h"
    #include "RenderContex.h"
    
    CRenderContex::CRenderContex(CDC *pDC)
    {
        ASSERT(pDC);
    
        BOOL bResult = FALSE;
        bResult = SetupPixelFormat(pDC);
        ASSERT(bResult);
    
        //Create Rendering Context
        m_hRC = ::wglCreateContext (pDC->GetSafeHdc ());
        ASSERT(m_hRC);
        //Make the RC Current
        bResult = ::wglMakeCurrent (pDC->GetSafeHdc (), m_hRC);
        ASSERT(bResult);
    }
    
    CRenderContex::~CRenderContex(void)
    {
        BOOL bResult = FALSE;
        //Make the RC non-current
        bResult = ::wglMakeCurrent (0,0);
        ASSERT(bResult);
    
        //Delete the rendering context
        bResult = ::wglDeleteContext (m_hRC);
        ASSERT(bResult);
    }
    
    //Setup Pixel Format
    BOOL CRenderContex::SetupPixelFormat(CDC *pDC)
    {
        static PIXELFORMATDESCRIPTOR pfd = 
        {
            sizeof(PIXELFORMATDESCRIPTOR),  // size of this pfd
            1,                              // version number
            PFD_DRAW_TO_WINDOW |            // support window
            PFD_SUPPORT_OPENGL |            // support OpenGL
            PFD_DOUBLEBUFFER,               // double buffered
            PFD_TYPE_RGBA,                  // RGBA type
            24,                             // 24-bit color depth
            0, 0, 0, 0, 0, 0,               // color bits ignored
            0,                              // no alpha buffer
            0,                              // shift bit ignored
            0,                              // no accumulation buffer
            0, 0, 0, 0,                     // accum bits ignored
            16,                             // 16-bit z-buffer
            0,                              // no stencil buffer
            0,                              // no auxiliary buffer
            PFD_MAIN_PLANE,                 // main layer
            0,                              // reserved
            0, 0, 0                         // layer masks ignored
        };
        int m_nPixelFormat = ::ChoosePixelFormat(pDC->GetSafeHdc(), &pfd);
        if ( m_nPixelFormat == 0 )
        {
            return FALSE;
        }
        if ( ::SetPixelFormat(pDC->GetSafeHdc(), m_nPixelFormat, &pfd) == FALSE)
        {
            return FALSE;
        }
        return TRUE;
    }

• 参考：http://www.cnblogs.com/phinecos/archive/2008/11/04/1326687.html